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Hot Jupiter WASP-18b: a too-close encounter 'Hot Jupiter' extrasolar planets are thought to have formed at some distance from their host stars and to have migrated inwards at a later date. These planets provide new perspectives on the evolution of planetary systems, and the discovery of WASP-18b, the closest-orbiting and most extreme hot Jupiter yet, provides a glimpse of what may be a planet nearing the end of its life. With a close orbit, high mass (ten times that of Jupiter), and brief (0.94-day) orbital period, WASP-18b has the strongest tidal interaction of any known star–planet system. We appear to be seeing WASP-18b in a rare and short-lived state as it spirals towards its host star, destined to be destroyed within the host star's lifetime. Alternatively, the tidal dissipation this system — and perhaps other hot Jupiters — must be much weaker than that in our Solar System. 'Hot Jupiters' abound in lists of known extrasolar planets. Those closest to their parent stars have strong tidal interactions, leading to the suggestion that systems such as OGLE-TR-56 could be used as tests of tidal dissipation theory. Here, the discovery of planet WASP-18b is reported, with an orbital period of 0.94 days and a tidal interaction an order of magnitude stronger than that of OGLE-TR-56b. Either WASP-18 is in a rare, short-lived state, or the tidal dissipation in this system must be weaker than in the Solar System. The ‘hot Jupiters’ that abound in lists of known extrasolar planets are thought to have formed far from their host stars, but migrate inwards through interactions with the proto-planetary disk from which they were born 1 , 2 , or by an alternative mechanism such as planet–planet scattering 3 . The hot Jupiters closest to their parent stars, at orbital distances of only ∼0.02 astronomical units, have strong tidal interactions 4 , 5 , and systems such as OGLE-TR-56 have been suggested as tests of tidal dissipation theory 6 , 7 . Here we report the discovery of planet WASP-18b with an orbital period of 0.94 days and a mass of ten Jupiter masses (10  M Jup ), resulting in a tidal interaction an order of magnitude stronger than that of planet OGLE-TR-56b. Under the assumption that the tidal-dissipation parameter Q of the host star is of the order of 10 6 , as measured for Solar System bodies and binary stars and as often applied to extrasolar planets, WASP-18b will be spiralling inwards on a timescale less than a thousandth that of the lifetime of its host star. Therefore either WASP-18 is in a rare, exceptionally short-lived state, or the tidal dissipation in this system (and possibly other hot-Jupiter systems) must be much weaker than in the Solar System.

The SuperWASP cameras are wide‐field imaging systems at the Observatorio del Roque de los Muchachos on the island of La Palma in the Canary Islands, and at the Sutherland Station of the South African Astronomical Observatory. Each instrument has a field of view of some 482 deg2with an angular scale of 13 \\documentclass{aastex} \\usepackage{amsbsy} \\usepackage{amsfonts} \\usepackage{amssymb} \\usepackage{bm} \\usepackage{mathrsfs} \\usepackage{pifont} \\usepackage{stmaryrd} \\usepackage{textcomp} \\usepackage{portland,xspace} \\usepackage{amsmath,amsxtra} \\usepackage[OT2,OT1]{fontenc} \\newcommand\\cyr{ \\renewcommand\\rmdefault{wncyr} \\renewcommand\\sfdefault{wncyss} \\renewcommand\\encodingdefault{OT2} \\normalfont \\selectfont} \\DeclareTextFontCommand{\\textcyr}{\\cyr} \\pagestyle{empty} \\DeclareMathSizes{10}{9}{7}{6} \\begin{document} \\landscape $\\farcs$\\end{document} 7 pixel−1, and is capable of delivering photometry with accuracy better than 1% for objects having \\documentclass{aastex} \\usepackage{amsbsy} \\usepackage{amsfonts} \\usepackage{amssymb} \\usepackage{bm} \\usepackage{mathrsfs} \\usepackage{pifont} \\usepackage{stmaryrd} \\usepackage{textcomp} \\usepackage{portland,xspace} \\usepackage{amsmath,amsxtra} \\usepackage[OT2,OT1]{fontenc} \\newcommand\\cyr{ \\renewcommand\\rmdefault{wncyr} \\renewcommand\\sfdefault{wncyss} \\renewcommand\\encodingdefault{OT2} \\normalfont \\selectfont} \\DeclareTextFontCommand{\\textcyr}{\\cyr} \\pagestyle{empty} \\DeclareMathSizes{10}{9}{7}{6} \\begin{document} \\landscape $V\\sim 7.0{\\mbox{--}} 11.5$ \\end{document} . Lower quality data for objects brighter than \\documentclass{aastex} \\usepackage{amsbsy} \\usepackage{amsfonts} \\usepackage{amssymb} \\usepackage{bm} \\usepackage{mathrsfs} \\usepackage{pifont} \\usepackage{stmaryrd} \\usepackage{textcomp} \\usepackage{portland,xspace} \\usepackage{amsmath,amsxtra} \\usepackage[OT2,OT1]{fontenc} \\newcommand\\cyr{ \\renewcommand\\rmdefault{wncyr} \\renewcommand\\sfdefault{wncyss} \\renewcommand\\encodingdefault{OT2} \\normalfont \\selectfont} \\DeclareTextFontCommand{\\textcyr}{\\cyr} \\pagestyle{empty} \\DeclareMathSizes{10}{9}{7}{6} \\begin{document} \\landscape $V\\sim 15.0$ \\end{document} are stored in the project archive. The systems, while designed to monitor fields with high cadence, are capable of surveying the entire visible sky every 40 minutes. Depending on the observational strategy, the data rate can be up to 100 Gbytes per night. We have produced a robust, largely automatic reduction pipeline and advanced archive, which are used to serve the data products to the consortium members. The main science aim of these systems is to search for bright transiting exoplanet systems suitable for spectroscopic follow‐up observations. The first 6 month season of SuperWASP‐North observations produced light curves of ∼6.7 million objects with 12.9 billion data points.

We report the discovery of a transiting planet with an orbital period of 3.05 days orbiting the star TYC 7247-587-1. The star, WASP-41, is a moderately bright G8 V V star ( V = 11.6 V = 11.6 ) with a metallicity close to solar ([Fe/H] = -0.08 ± 0.09 [ Fe / H ] = - 0.08 ± 0.09 ). The star shows evidence of moderate chromospheric activity, both from emission in the cores of the Ca iiH and K ines and photometric variability with a period of 18.4 days and an amplitude of about 1%. We use a new method to show quantitatively that this periodic signal has a low false-alarm probability. The rotation period of the star implies a gyrochronological age for WASP-41 of 1.8 Gyr with an error of about 15%. We have used a combined analysis of the available photometric and spectroscopic data to derive the mass and radius of the planet (0.92 ± 0.06 M Jup 0.92 ± 0.06     M Jup ,1.20 ± 0.06 R Jup 1.20 ± 0.06     R Jup ). Further observations of WASP-41 can be used to explore the connections between the properties of hot Jupiter planets and the level of chromospheric activity in their host stars.

ABSTRACT We present the DONUTS autoguiding algorithm, designed to fix stellar positions at the sub-pixel level for high-cadence time-series photometry, and also capable of autoguiding on defocused stars. DONUTS was designed to calculate guide corrections from a series of science images and recentre telescope pointing between each exposure. The algorithm has the unique ability of calculating guide corrections from undersampled to heavily defocused point spread functions. We present the case for why such an algorithm is important for high precision photometry and give our results from off and on-sky testing. We discuss the limitations of DONUTS and the facilities where it soon will be deployed.

We present the prototype telescope for the Next Generation Transit Survey, which was built in the UK in 2008/2009 and tested on La Palma in the Canary Islands in 2010. The goals for the prototype system were severalfold: to determine the level of systematic noise in an NGTS-like system; demonstrate that we can perform photometry at the (sub) millimagnitude level on transit timescales across a wide-field; show that it is possible to detect transiting super-Earth and Neptune-sized exoplanets and prove the technical feasibility of the proposed planet survey. We tested the system for around 100 nights and met each of the goals above. Several key areas for improvement were highlighted during the prototyping phase. They have been subsequently addressed in the final NGTS facility, which was recently commissioned at ESO Cerro Paranal, Chile.

We report the discovery of a new transiting planet from the WASP survey. WASP-135b is a hot Jupiter with radius 1.30 0.09 RJup, mass 1.90 0.08 MJup, and an orbital period of 1.401 days. Its host is a Sun-like star, with a G5 spectral type and a mass and radius of 0.98 0.06 M☉ and 0.96 0.05 R☉, respectively. The proximity of the planet to its star means that WASP-135b receives high levels of insolation, which may be the cause of its inflated radius. Additionally, we report weak evidence of a transfer of angular momentum from the planet to its host star.

We report the discovery of a transiting planet orbiting the star TYC 2-1155-1. The star, WASP-32, is a moderately bright ( V = 11.3 V = 11.3 ) solar-type star ( T eff = 6100 ± 100 K T eff = 6100 ± 100     K ,[Fe/H] = -0.13 ± 0.10 [ Fe / H ] = - 0.13 ± 0.10 ). The light curve of the star obtained with the WASP-South and WASP-North instruments shows periodic transitlike features with a depth of about 1% and a duration of 0.10 day every 2.72 days. The presence of a transitlike feature in the light curve is confirmed using z z -band photometry obtained with Faulkes Telescope North. High-resolution spectroscopy obtained with the Coralie spectrograph confirms the presence of a planetary mass companion. From a combined analysis of the spectroscopic and photometric data, assuming that the star is a typical main-sequence star, we estimate that the planet has a mass M p M p of3.60 ± 0.07 M Jup 3.60 ± 0.07     M Jup and a radius R p = 1.19 ± 0.06 R Jup R p = 1.19 ± 0.06     R Jup . WASP-32 is one of a small group of hot Jupiters with masses greater than3 M Jup 3     M Jup . We find that some stars with hot Jupiter companions and with masses M ⋆ ≈ 1.2 M ⊙ M ⋆ ≈ 1.2     M ⊙ , including WASP-32, are depleted in lithium and that the majority of these stars have lithium abundances similar to field stars.

We present the discovery by the WASP-South survey of three planets transiting moderately bright stars (V 11). WASP-120 b is a massive (4.85 MJup) planet in a 3.6-day orbit that we find likely to be eccentric ( e = 0.059 − 0.018 + 0.025 ) around an F5 star. WASP-122 b is a hot Jupiter (1.28 MJup, 1.74 RJup) in a 1.7-day orbit about a G4 star. Our predicted transit depth variation caused by the atmosphere of WASP-122 b suggests it is well suited to characterization. WASP-123 b is a hot Jupiter (0.90 MJup, 1.32 RJup) in a 3.0-day orbit around an old (∼7 Gyr) G5 star.

The majority of extra-solar planets have been discovered (or confirmed after follow-up) through radial-velocity (RV) surveys. Using ground-based spectrographs such as High Accuracy Radial Velocity Planetary Search (HARPS) and HARPS-North, it is now possible to detect planets that are only a few times the mass of the Earth. However, the presence of dark spots on the stellar surface produces RV signals that are very similar in amplitude to those caused by orbiting low-mass planets. Disentangling these signals has thus become the biggest challenge in the detection of Earth-mass planets using RV surveys. To do so, we use the star's lightcurve to model the RV variations produced by spots. Here we present this method and show the results of its application to CoRoT-7.

We present the discovery by the WASP-South survey of three planets transiting moderately bright stars (V ≈ 11). WASP-120 b is a massive (4.85 M Jup) planet in a 3.6-day orbit that we find likely to be eccentric ( e = 0.059 − 0.018 + 0.025 ) around an F5 star. WASP-122 b is a hot Jupiter (1.28 M Jup, 1.74 RJup) in a 1.7-day orbit about a G4 star. Our predicted transit depth variation caused by the atmosphere of WASP-122b suggests it is well suited to characterization. WASP-123 b is a hot Jupiter (0.90 M Jup, 1.32 R Jup) in a 3.0-day orbit around an old (∼7 Gyr) G5 star.